diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
index 9fcf09f2ef00..c187a9e62bdb 100644
--- a/kernel/bpf/cgroup_iter.c
+++ b/kernel/bpf/cgroup_iter.c
@@ -164,16 +164,30 @@ static int cgroup_iter_seq_init(void *priv, struct bpf_iter_aux_info *aux)
 	struct cgroup_iter_priv *p = (struct cgroup_iter_priv *)priv;
 	struct cgroup *cgrp = aux->cgroup.start;
 
+	/* bpf_iter_attach_cgroup() has already acquired an extra reference
+	 * for the start cgroup, but the reference may be released after
+	 * cgroup_iter_seq_init(), so acquire another reference for the
+	 * start cgroup.
+	 */
 	p->start_css = &cgrp->self;
+	css_get(p->start_css);
 	p->terminate = false;
 	p->visited_all = false;
 	p->order = aux->cgroup.order;
 	return 0;
 }
 
+static void cgroup_iter_seq_fini(void *priv)
+{
+	struct cgroup_iter_priv *p = (struct cgroup_iter_priv *)priv;
+
+	css_put(p->start_css);
+}
+
 static const struct bpf_iter_seq_info cgroup_iter_seq_info = {
 	.seq_ops		= &cgroup_iter_seq_ops,
 	.init_seq_private	= cgroup_iter_seq_init,
+	.fini_seq_private	= cgroup_iter_seq_fini,
 	.seq_priv_size		= sizeof(struct cgroup_iter_priv),
 };